Polymerizable composition and use thereof

ABSTRACT

The present invention provides a solid polymer electrolyte; a polymerizable composition having low viscosity and excellent processability for obtaining the solid polymer electrolyte; and a polymerizable compound having low viscosity, and good polymerizability and stability for use in the polymerizable composition. The present invention also provides primary and secondary batteries capable of working with high capacity and current; an electric double-layer capacitor ensuring high output voltage, large takeout current, and good processability; and an electrochromic device favored with high response speed. Each thereof use the solid polymer electrolyte of the present invention and are ensured with long life, excellent safety free of liquid leakage, high reliability and production at a low cost. A solid polymer electrolyte, including a carbonate-based polymer in which a branched chain is introduced and having a high dielectric constant and a wide electrochemical stability range, having excellent processability, good safety and high ionic conductivity, is provided.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is an application filed under 35 U.S.C. §111(a)claiming benefit pursuant to 35 U.S.C. §119(e)(1) of the filing date ofProvisional Application No. 60/245,717 filed Nov. 6, 2000 pursuant to 35U.S.C. §111(b).

FIELD OF THE INVENTION

[0002] The present invention relates to a highly ion conductive solidpolymer electrolyte comprising a polymer compound containing a branchedcarbonate group as a main component and an electrolyte salt, which isuseful for various electrochemical devices; a polymerizable compound anda polymerizable composition for obtaining the solid polymer electrolyte;and a battery, an electric double-layer capacitor and an electrochromicdevice using the solid polymer electrolyte.

BACKGROUND OF THE INVENTION

[0003] With the popularization of portable instruments in recent years,various batteries and capacitor devices such as electric double-layercapacitor are becoming lightweight and also, the production thereof isabruptly increasing. Furthermore, in view of the popularization in thefuture of hybrid car, electric car and the like, which are highlyexpected from an environmental aspect, there is a demand for capacitordevices to have larger size and higher performance. Among the batteries,nonaqueous batteries, such as Li primary battery and Li ion secondarybattery are growing because of their high voltage and high energydensity. Also, electric double-layer capacitors using an active carbonelectrode having a high specific surface area as the polarizableelectrode are also growing because of their high power density.

[0004] With respect to the display material, flatness and smallthickness are being taken notice of and studies on improvements ofliquid crystal, organic electroluminescent device and electrochromic(ECD) devices are aggressively proceeding. Among these, an ECD deviceexhibits color change by an electrochemical reaction, does notspontaneously emit light and is low in response speed. However, becauseof its memory property, the ECD device is attracting attention in viewof its original purpose such as light-shielding glass, rather than as adisplay device.

[0005] These capacitor devices and ECD devices each uses anelectrochemical reaction and the electrolyte material used therein isdemanded to have higher performance. The properties required for theelectrolyte material include high ionic conductivity, broad range ofelectrochemical stability, impregnation property into variouselectrodes, heat resistance, environmental resistance and safety. Inparticular, a Li (ion) battery, and a nonaqueous electric double-layercapacitor as a nonaqueous capacitor device are attracting attention atpresent because of their high voltage and high energy density. Theelectrolyte material used therefor is particularly demanded to satisfythe following requirements: to be improved in the ionic conductivity, tohave an electrochemical stability range broad enough to endure highvoltage use, to be easily compounded with various electrode materialsand to have excellent safety.

[0006] Conventional liquid electrolytes have a problem in that thesafety and reliability decrease due to liquid leakage or volatilization.In order to solve this problem, a solid polymer electrolyte obtained bysolidifying an electrolyte salt with a polymer or the like is beingtaken notice of in recent years. Examples thereof include a solidpolymer electrolyte characterized by the introduction of a polyetherchain into a polymer (see, JP-A-4-211412 (the term “JP-A” as used hereinmeans an “unexamined published Japanese patent application”)). Thissolid polymer electrolyte is improved in safety and stability, butsuffers from reduction in ionic conductivity or deterioration in thecompounding property with various electrode materials and from a problemthat when the solid polymer electrolyte is used in variouselectrochemical devices, the device has small takeout current.

[0007] In order to solve these problems of the solid polymerelectrolyte, the present inventors have proposed a solid polymerelectrolyte using a polymer having a carbonate structure, and apolymerizable compound and a polymerizable composition for obtaining thesolid polymer electrolyte (see, for example, JP-A-11-149823 andJP-A-11-149824).

[0008] JP-A-1-311573 describes an electrochemical apparatus using asolid polymer electrolyte comprising a polymer having bonded thereto aside chain having no active hydrogen atom, where poly(ethylene ethercarbonate) end capped with methacrylate is an example of the polymer.

[0009] JP-A-9-147912 describes a solid polymer electrolyte having bothflexibility and rigidity, and improved in adhesive property to alkalielectrode and in interface resistance by using a copolymer ofpoly(alkylene(ether)carbonate end capped with methacrylate, similar toJP-A-1-311573, and a polyether end capped with methacrylate.

[0010] Also, JP-A-62-30147 and JP-A-62-30148 disclose a solid polymerelectrolyte using polyalkylene carbonate having a specific structure,which enhances the compatibility of an organic solvent or an electrolytesalt and improves the mechanical properties.

[0011] The carbonate structure has a high dielectric constant andtherefore, improves the solubility of electrolyte salt and compatibilitywith various organic solvents and in turn, the solid polymer electrolyteis improved in ionic conductivity. Furthermore, a broad electrochemicalstability range is ensured, which is suited for the fabrication ofdevices having a high voltage. However, a polymer having a carbonatestructure has a high viscosity compared with polyether-based polymersconventionally used for the polymer solid electrolyte and suffers frompoor compounding property with various electrode materials.

SUMMARY OF THE INVENTION

[0012] An object of the present invention is to improve theprocessability and compounding property of a solid polymer electrolytewith an electrode of the carbonate-based polymer having high dielectricconstant, high ionic conductivity and high electrochemical stability,thereby providing a solid polymer electrolyte favored with high ionicconductivity and excellent in durability, electrochemical stability,processability, safety and reliability.

[0013] Another object of the present invention is to provide a primarybattery and a secondary battery facilitated in the formation into a thinfilm, broad in operation voltage, capable of working with high capacityand high current, favored with a long life and excellent in reliabilityand processability.

[0014] Still another object of the present invention is to provide anelectric double-layer capacitor having high output voltage, largetakeout current, good processability, long life and excellentreliability by using the above-described carbonate-based solid polymerelectrolyte.

[0015] Still another object of the present invention is to provide anelectrochromic device having good processability, high response speed,long life and excellent reliability by using the above-describedcarbonate-based solid polymer electrolyte.

[0016] As a result of extensive investigations to solve theabove-described problems, the present inventors discovered that byintroducing a branched chain into a carbonate chain to reduce theviscosity of a carbonate-based polymer, a solid polymer electrolytehaving excellent processability can be obtained. Furthermore, when thecarbonate-based polymer having introduced thereinto a branched chain isdiluted with a solvent or the like to reduce the viscosity, a highereffect of reducing the viscosity can be brought out. This is presumed asresulting from the interaction between polymers being weakened by theintroduction of a branched chain.

[0017] The present inventors also discovered that by polymerizing a lowmolecular weight polymerizable compound having a branched carbonatechain, a solid polymer electrolyte having excellent compounding propertywith an electrode material of various electrochemical devices can beobtained.

[0018] Still further, the present inventors discovered that by using theabove-described solid polymer electrolyte, a primary battery and asecondary battery having broad operation voltage, capability of workingwith high capacity and high current, long life, no liquid leakage andexcellent safety and reliability; an electric double-layer capacitorhaving high output voltage, large takeout current, good processability,long life, no liquid leakage and excellent safety and reliability; andan electrochromic device having high response speed, long life, noliquid leakage and excellent reliability can be obtained.

[0019] That is, the present invention provides a solid polymerelectrolyte, a polymerizable compound composition for a solid polymerelectrolyte, a battery, an electric double-layer capacitor and anelectrochromic device using these, and provides the followingembodiments.

[0020] (1) A solid polymer electrolyte comprising a polymer compoundhaving a branched carbonate structure represented by formula (1) as apartial structure and at least one electrolyte salt:

[0021] wherein R¹ and R² each represents a hydrogen atom, an alkyl grouphaving from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10carbon atoms or an alkoxyalkyl group having from 1 to 10 carbon atoms,the alkyl, alkoxy or alkoxyalkyl group may have a linear, branched orcyclic structure, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, and R¹, R², m or n present in plurality within thesame molecule may be the same or different, provided that R¹ or R²present in plurality within the same molecule are not a hydrogen atom atthe same time.

[0022] (2) A solid polymer electrolyte comprising a polymer compoundhaving a branched carbonate structure represented by formula (2) as apartial structure and at least one electrolyte salt:

[0023] wherein R³ represents a hydrogen atom, an alkyl group having from1 to 10 carbon atoms, an alkoxy group having from 1 to 10 carbon atomsor an alkoxyalkyl group having from 1 to 10 carbon atoms, the alkyl,alkoxy or alkoxyalkyl group may have a linear, branched or cyclicstructure, m represents an integer of 3 to 10, n represents an integerof 1 to 500, and R³, m or n present in plurality within the samemolecule may be the same or different, provided that R³ present inplurality within the same molecule are not a hydrogen atom at the sametime.

[0024] (3) A solid polymer electrolyte which is a polymer of apolymerizable compound having a branched carbonate structure describedin (1) or (2) above and a polymerizable functional group represented bythe following formula (3) and/or (4):

[0025] wherein R⁴ represents a hydrogen atom or an alkyl group havingfrom 1 to 10 carbon atoms, R⁶ represents a hydrogen atom, an alkyl grouphaving from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10carbon atoms or an alkoxyalkyl group having from 1 to 10 carbon atoms,the alkyl, alkoxy or alkoxyalkyl group may have a linear, branched orcyclic structure, R⁵ represents a divalent group which may contain aheteroatom and may have a linear, branched or cyclic structure, and xrepresents 0 or 1, provided that R⁴, R⁵, R⁶ or x present in pluralitywithin the same molecule may be the same or different.

[0026] (4) The solid polymer electrolyte as described in (3) above,wherein the polymerizable compound has a mass average molecular weightof about 100 to about 3,000.

[0027] (5) The solid polymer electrolyte as described in (3) or (4)above, wherein the polymerizable compound is liquid at room temperatureand the viscosity thereof is about 5,000 mPa·S (25° C.) or less.

[0028] (6) The solid polymer electrolyte as described in any one of (1)to (5) above, which comprises at least one organic solvent.

[0029] (7) A polymerizable composition for solid polymer electrolytes,comprising at least one polymerizable compound described in any one of(3), (4) and (5) above and at least one electrolyte salt.

[0030] (8) The polymerizable composition for solid polymer electrolytesas described in (7) above, which comprises at least one organic solvent.

[0031] (9) The polymerizable composition for solid polymer electrolytesas described in 8) above, wherein the viscosity is about 6.0 mPa·S (25°C.) or less.

[0032] (10) A solid polymer electrolyte obtained by polymerizing thepolymerizable composition described in (7) above.

[0033] (11) A solid polymer electrolyte obtained by polymerizing thepolymerizable composition described in (8) above.

[0034] (12) A solid polymer electrolyte obtained by polymerizing thepolymerizable composition described in (9) above.

[0035] (13) The solid polymer electrolyte as described in any one of(1), (2), (10), (11) and (12) above, wherein the electrolyte salt is atleast one electrolyte salt selected from an alkali metal salt, aquaternary ammonium salt and a quaternary phosphonium salt.

[0036] (14) The polymerizable composition for a solid polymerelectrolyte as described in any one of (7), (8) and (9) above, whereinthe electrolyte salt is at least one electrolyte salt selected from analkali metal salt, a quaternary ammonium salt and a quaternaryphosphonium salt.

[0037] (15) The solid polymer electrolyte as described in any one of(6), (11) and (12) above, wherein the organic solvent is at least oneorganic solvent selected from carbonates, aliphatic esters, ethers,lactones, sulfoxides and amides.

[0038] (16) The polymerizable composition for solid polymer electrolytesas described in (8) or (9) above, wherein the organic solvent is atleast one organic solvent selected from carbonates, aliphatic esters,ethers, lactones, sulfoxides and amides.

[0039] (17) A battery using a solid polymer electrolyte described in anyone of (1) to (6), (10) to (13) and (15) above.

[0040] (18) The battery as described in (17) above, which is a lithiumprimary or lithium secondary battery using, as the electrolyte salt, atleast one member selected LiPF₆, LiBF₄, LiAsF₆ and LiN(A-SO₂)₂, whereinA represents a perfluoroalkyl group having from 1 to 10 carbon atoms.

[0041] (19) An electric double-layer capacitor using a solid polymerelectrolyte described in any one of (1) to (6), (10) to (13) and (15)above.

[0042] (20) An electrochromic device using a solid polymer electrolytedescribed in any one of (1) to (6), (10) to (13) and (15) above.

[0043] (21) A polymerizable compound represented by formula (5):

[0044] wherein R¹ and R² each represents a hydrogen atom, an alkyl grouphaving from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10carbon atoms or an alkoxyalkyl group having from 1 to 10 carbon atoms,the alkyl, alkoxy or alkoxyalkyl group may have a linear, branched orcyclic structure, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, R⁴ represents hydrogen or an alkyl group havingfrom 1 to 10 carbon atoms, the alkyl group may have a linear, branchedor cyclic structure, R⁷ represents a chained, branched and/or cyclicorganic group having from 1 to 30 carbon atoms, which may contain aheteroatom and/or an unsaturated bond, and R¹, R², R⁴, R⁷, m or npresent in plurality within the same molecule may be the same ordifferent, provided that R¹ or R² present in plurality within the samemolecule are not a hydrogen atom at the same time.

[0045] (22) A polymerizable compound represented by formula (6):

[0046] wherein R¹ and R² each represents a hydrogen atom, an alkyl grouphaving from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10carbon atoms or an alkoxyalkyl group having from 1 to 10 carbon atoms,the alkyl, alkoxy or alkoxyalkyl group may have a linear, branched orcyclic structure, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, x represents 0 or 1, R⁴ represents a hydrogen atomor an alkyl group having from 1 to 10 carbon atoms, the alkyl group mayhave a linear, branched or cyclic structure, R⁷ represents a chained,branched and/or cyclic organic group having from 1 to 30 carbon atoms,which may contain a heteroatom and/or an unsaturated bond, R⁶ representsa hydrogen atom, an alkyl group having from 1 to 10 carbon atoms, analkoxy group having from 1 to 10 carbon atoms or an alkoxyalkyl grouphaving from 1 to 10 carbon atoms, the alkyl, alkoxy or alkoxyalkyl groupmay have a linear, branched or cyclic structure, R⁷ represents achained, branched and/or cyclic organic group having from 1 to 30 carbonatoms, which may contain a heteroatom and/or an unsaturated bond, andR¹, R², R⁴, R⁵, R⁶, R⁷, m or n present in plurality within the samemolecule may be the same or different, provided that R¹ or R² present inplurality within the same molecule are not a hydrogen atom at the sametime.

BRIEF DESCRIPTION OF THE DRAWINGS

[0047]FIG. 1 is a schematic cross-sectional view showing a thin batteryaccording to one embodiment of the battery of the present invention.

[0048]FIG. 2 is a schematic cross-sectional view showing one embodimentof a solid electric double-layer capacitor of the present invention.

[0049]FIG. 3 is a schematic cross-sectional view showing one embodimentof a solid thin ECD of the present invention.

DESCRIPTION OF THE PRESENT INVENTION

[0050] The present invention is described in detail below.

[0051] (Solid Polymer Electrolyte)

[0052] The solid polymer electrolyte of the present inventionfundamentally comprises (a) a polymer compound and (b) an electrolytesalt as main constituent components and may further comprise (c) anorganic solvent and other additives such as inorganic oxide. Respectivecomponents are described in detail below.

[0053] (a) Polymer Compound

[0054] The polymer compound as a main constituent component of the solidpolymer electrolyte of the present invention is electronicallynon-conducting and can absorb and hold various organic polar solvents.This compound contains a crosslinked and/or side chain group having abranched carbonate structure represented by the following formula (1):

[0055] wherein R¹ and R² each represents a hydrogen atom, an alkyl grouphaving from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10carbon atoms or an alkoxyalkyl group having from 1 to 10 carbon atoms,the alkyl, alkoxy or alkoxyalkyl group may have a linear, branched orcyclic structure, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, and R¹, R², m or n present in plurality within thesame molecule may be the same or different, provided that R¹ or R²present in plurality within the same molecule are not a hydrogen atom atthe same time.

[0056] In the formula above, if m is too large, the relative ratio ofthe carbonate group in the polymer compound becomes small and this isdisadvantageous in that the dielectric constant decreases, theelectrolyte salt is difficult to dissociate and the polymer compound isincreased in the hydrophobicity and decreased in the compatibility withvarious polar solvents. If m is excessively small, the flexibility ofthe polymer decreases and at the time of synthesis, production of cyclicby-products disadvantageously increases. m is preferably from 3 to 8.

[0057] When a branched chain is introduced into a polymer compound as inthe formula above, the polymer compound is reduced in the crystallinityand in the melting point, glass transition point or viscosity. However,if the number of carbon atoms in R¹ or R² is excessively large, thehydrophobicity of the polymer compound increases and this isdisadvantageous in that the dielectric constant decreases, theelectrolyte salt is difficult to dissociate and compatibility withvarious polar solvents decreases. The number of carbon atoms in R¹ or R²is preferably from 1 to 5.

[0058] In the polymer used for the solid polymer electrolyte of thepresent invention, the number n of continuous repetition of thecarbonate structure represented by formula (1) is from 1 to 500,preferably 5 to 300.

[0059] In another embodiment, the polymer compound for use in thepresent invention comprises a crosslinked and/or side chain group havinga branched carbonate structure represented by formula (2):

[0060] wherein R³ represents a hydrogen atom, an alkyl group having from1 to 10 carbon atoms, an alkoxy group having from 1 to 10 carbon atomsor an alkoxyalkyl group having from 1 to 10 carbon atoms, the alkyl,alkoxy or alkoxyalkyl group may have a linear, branched or cyclicstructure, m represents an integer of 3 to 10, n represents an integerof 1 to 500, and R³, m or n present in plurality within the samemolecule may be the same or different, provided that R³ present inplurality within the same molecule are not a hydrogen atom at the sametime.

[0061] In the formula above, if m is too large, the relative ratio ofthe carbonate group in the polymer compound becomes small, which isdisadvantageous in that the dielectric constant decreases, theelectrolyte salt is difficult to dissociate and the polymer compound isincreased in hydrophobicity and decreased in compatibility with variouspolar solvents. If m is excessively small, the flexibility of thepolymer decreases and during synthesis, production of cyclic by-productsdisadvantageously increases. m is preferably from 3 to 8.

[0062] When a branched chain is introduced into a polymer compound as inthe formula above, the polymer compound is reduced in crystallinity andin melting point, glass transition point or viscosity. However, if thenumber of carbon atoms in R³ is excessively large, the hydrophobicity ofthe polymer compound increases, which is disadvantageous in that thedielectric constant decreases, the electrolyte salt is difficult todissociate and compatibility with various polar solvents decreases. Thenumber of carbon atoms in R³ is preferably from 1 to 5.

[0063] In the polymer used for the solid polymer electrolyte of thepresent invention, the number n of continuous repetition of thecarbonate structure represented by formula (2) is from 1 to 500,preferably 5 to 300.

[0064] The polymer for use in the solid polymer electrolyte of thepresent invention is preferably (A) a polymer obtained by polymerizingat least one polymerizable compound having a carbonate structurerepresented by formula (1) or (2) and having a polymerizable functionalgroup represented by the following formula (3) and/or (4):

[0065] wherein R⁴ represents a hydrogen atom or an alkyl group havingfrom 1 to 10 carbon atoms, R⁶represents a hydrogen atom, an alkyl grouphaving from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10carbon atoms or an alkoxyalkyl group having from 1 to 10 carbon atoms,the alkyl, alkoxy or alkoxyalkyl group may have a linear, branched orcyclic structure, R⁵ represents a divalent group which may contain aheteroatom and may have a linear, branched or cyclic structure, and xrepresents 0 or 1, provided that R⁴, R⁵, R⁶ or x present in pluralitywithin the same molecule may be the same or different, because theobtained solid polymer electrolyte is facilitated in processing or incompounding with an electrode used for various electrochemical devices.

[0066] A polymer obtained by polymerizing a compound having onefunctional group represented by formula (3) and/or (4) has nocrosslinked structure and is deficient in the film strength. Therefore,when this polymer is formed into a thin film, short circuit may occur.Accordingly, the polymer is preferably crosslinked by copolymerizingwith a polyfunctional polymerizable compound having two or morefunctional groups represented by formula (3) and/or (4), or preferablyused in combination with a polymer obtained from a polyfunctionalpolymerizable compound having two or more functional groups representedby formula (3) and/or (4). However, in the case where low viscosity isintended, a low molecular weight form of a monofunctional polymerizablecompound having one functional group is preferably used in an amount aslarge as possible, because the crosslinking density does not increaseafter the polymerization and low viscosity can be attained. The amountof the monofunctional polymerizable compound mixed varies depending onthe molecular weight or structure and cannot be indiscriminatelylimited, however, it is preferably from 20 to 90% by mass, morepreferably from 40 to 85% by mass, based on all polymerizable compounds.

[0067] Also, the polymer for use in the solid polymer electrolyte of thepresent invention may be (B) a copolymer obtained by copolymerizing atleast one polymerizable compound having a polymerizable functional grouprepresented by formula (3) and/or (4) and at least one polymerizablecompound having a functional group copolymerizable with theabove-described polymerizable compound and a carbonate structurerepresented by formula (1), or (C) a mixture of at least one polymercompound having a carbonate structure represented by formula (1) and apolymer obtained by polymerizing at least one polymerizable compoundhaving a polymerizable functional group represented by formula (3)and/or (4).

[0068] The polymerizable compound for use in the solid polymerelectrolyte of the present invention is preferably liquid at roomtemperature and low in viscosity in view of processability when forminga solid polymer electrolyte by polymerizing the polymerizable compoundor a polymerizable composition resulting from mixing with an electrolytesalt or the like, or in view of impregnating ability when performing thepolymerization by injecting the compound or composition into anelectrochemical device. The viscosity at 25° C. of the polymerizablecompound for use in the solid polymer electrolyte of the presentinvention is preferably about 10,000 mPa·s or less, more preferablyabout 5,000 mPa·s.

[0069] The polymerizable compound for use in the solid polymerelectrolyte of the present invention preferably has a molecular weightas small as possible to have a low viscosity. However, if the molecularweight is excessively small, the crosslinking density or crystallinityincreases after the polymerization, which is disadvantageous in that thesolid polymer electrolyte is reduced in temperature characteristics ofionic conductivity or in contacting property with variouselectrochemical device materials. The viscosity is affected not only bythe molecular weight, but also by the structure such as branched chain.Therefore, the molecular weight of the polymerizable compound for use inthe solid polymer electrolyte of the present invention is preferablyfrom about 100 to about 3,000, more preferably from about 150 to about1,500.

[0070] Specific examples of the polymerizable compound (A) include thecompounds represented by the following formulae (5) and (6):

[0071] wherein R¹ and R² each represents a hydrogen atom, an alkyl grouphaving from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10carbon atoms or an alkoxyalkyl group having from 1 to 10 carbon atoms,the alkyl, alkoxy or alkoxyalkyl group may have a linear, branched orcyclic structure, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, R⁴ represents hydrogen or an alkyl group havingfrom 1 to 10 carbon atoms, the alkyl group may have a linear, branchedor cyclic structure, R⁷ represents a chained, branched and/or cyclicorganic group having from 1 to 30 carbon atoms, which may contain aheteroatom and/or an unsaturated bond, and R¹, R², R⁴, R⁷, m or npresent in plurality within the same molecule may be the same ordifferent, provided that R¹ or R² present in plurality within the samemolecule are not a hydrogen atom at the same time.

[0072] wherein R¹ and R² each represents a hydrogen atom, an alkyl grouphaving from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10carbon atoms or an alkoxyalkyl group having from 1 to 10 carbon atoms,the alkyl, alkoxy or alkoxyalkyl group may have a linear, branched orcyclic structure, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, x represents 0 or 1, R⁴ represents a hydrogen atomor an alkyl group having from 1 to 10 carbon atoms, the alkyl group mayhave a linear, branched or cyclic structure, R⁷ represents a chained,branched and/or cyclic organic group having from 1 to 30 carbon atoms,which may contain a heteroatom and/or an unsaturated bond, R⁶ representsa hydrogen atom, an alkyl group having from 1 to 10 carbon atoms, analkoxy group having from 1 to 10 carbon atoms or an alkoxyalkyl grouphaving from 1 to 10 carbon atoms, the alkyl, alkoxy or alkoxyalkyl groupmay have a linear, branched or cyclic structure, R⁷ represents achained, branched and/or cyclic organic group having from 1 to 30 carbonatoms, which may contain a heteroatom and/or an unsaturated bond, andR¹, R², R⁴, R⁵, R⁶, R⁷, m or n present in plurality within the samemolecule may be the same or different, provided that R¹ or R² present inplurality within the same molecule are not a hydrogen atom at the sametime.

[0073] The method for synthesizing the polymerizable compound having acarbonate structure represented by formula (1) and a polymerizablefunctional group represented by formula (3) is not particularly limitedand the polymerizable compound can be easily obtained, for example, bydehydration-condensing an acid having a polymerizable functional group,such as acroyl acid, and a carbonate-ol having a hydroxyl group at theterminal, in the presence of an acid catalyst or the like as shownbelow.

[0074] wherein R¹, R², R⁴, m and n have the same meanings as in formula(5).

[0075] The method for synthesizing the polymerizable compound having acarbonate structure represented by formula (1) and a polymerizablefunctional group represented by formula (4) is not particularly limitedand the polymerizable compound can be easily obtained, for example, byreacting an acryloyl-based isocyanate compound represented by theformula:

[0076] with a carbonate-ol having a hydroxyl group at the terminal, inthe presence of a urethanization reaction catalyst as shown below.

[0077] wherein R¹, R², R⁴, R⁵, n, m and x have the same meanings as informula (6).

[0078] The polymer compound obtained by polymerizing a compound having apolymerizable functional group represented by formula (4) contains aurethane group, which is advantageous in that the dielectric constant ishigh and the solid polymer electrolyte obtained is increased in ionicconductivity. Furthermore, the compound having a polymerizablefunctional group represented by (4) has good polymerizability, and whenthe compound is formed into a thin film, the film advantageously has asufficiently high film strength and a large capacity for including anelectrolytic solution.

[0079] The polymerizable compound having a carbonate structurerepresented by formula (1) and, at the same time, having a polymerizablefunctional group represented by formula (3) and/or (4), which issuitable for obtaining the polymer for use in the solid polymerelectrolyte of the present invention, is polymerized in the presence ofa polymerization initiator to form a solid polymer electrolyte. Thesepolymerizable compounds can be used individually or in combination oftwo or more thereof. Also, at least one of these polymerizable compoundsmay be copolymerized with another polymerizable compound.

[0080] Another polymerizable compound copolymerizable with thepolymerizable compound having a carbonate structure represented byformula (1) and a polymerizable functional group represented by formula(3) and/or (4) is not particularly limited and examples thereof include(meth)acrylic acid alkyl esters such as methyl methacrylate and n-butylacrylate; various urethane acrylates; (meth)acrylamide-based compoundssuch as acrylamide, methacrylamide, N,N-dimethylacrylamide,N,N-dimethyllmethacrylamide, vinylene carbonate, (meth)acryloylcarbonate, N-vinylpyrrolidone, acryloylmorpholine,methacryloylmorpholine, N,N-dimethylaminopropyl (meth)acrylamide;styrene-based compounds such as styrene and α-methylstyrene;N-vinylamide-based compounds such as N-vinylacetamide andN-vinylformamide; and alkyl vinyl ethers such as ethyl vinyl ether.Among these, preferred are (meth)acrylic acid esters and urethane(meth)acrylates.

[0081] The polymer for use in the solid polymer electrolyte of thepresent invention may be a polymer obtained from at least onepolymerizable compound having a carbonate structure represented byformula (1) and a polymerizable functional group represented by formula(3) and/or (4), and/or a mixture of a copolymer using theabove-described polymerizable compound as a copolymerization componentwith another polymer, examples of which include polyethylene oxides,polypropylene oxides, polyacrylonitrile, poly(meth)acrylic acid esters,polystyrene, polyphosphagene and polymers such as polysiloxane,polysilane, polyvinylidene fluoride and polytetrafluoroethylene.

[0082] The amount of the structural unit derived from the polymer havinga carbonate structure represented by formula (1) varies depending onwhether the polymerizable compound having a carbonate structurerepresented by formula (1) and, at the same time, having a polymerizablefunctional group represented by formula (3) and/or (4) ishomopolymerized, copolymerized with another copolymerization componentor mixed with another polymer, and thus cannot be indiscriminatelyspecified. However, in view of ionic conductivity, film strength, heatresistance and current characteristics of the solid polymer electrolyteobtained, the content thereof is preferably 50% by mass or more, morepreferably 70% by mass or more, based on the total amount of the polymercomponents.

[0083] The polymerization of the polymerizable compound having acarbonate structure represented by formula (1) and a polymerizablefunctional group represented by formula (3) and/or (4) may be performedby a general method using the polymerizability of acryloyl ormethacryloyl group as the functional group. More specifically, thepolymerizable compound alone or a mixture of the polymerizable compoundand another polymerizable compound copolymerizable therewith may besubjected to radical polymerization, cationic polymerization or anionicpolymerization using a radical polymerization catalyst such as2,2′-azobisisobutyronitrile (AIBN) and benzoyl peroxide (BPO), acationic polymerization catalyst such as protonic acid (e.g., CF₃COOH)and Lewis acid (e.g., BF₃, AlCl₃), or an anionic polymerization catalystsuch as butyl lithium, sodium naphthalene and lithium alkoxide.Furthermore, the polymerizable compound or polymerizable mixture mayalso be polymerized after forming it into a film or the like or afterinjecting or impregnating it into various electrode materials.

[0084] (b) Electrolyte Salt

[0085] The kind of electrolyte salt used in the present invention is notparticularly limited and any electrolyte may be used as long as itcontains an ion intended to be used as a charge carrier. The electrolytesalt preferably has a large dissociation constant in a solid polymerelectrolyte, and examples thereof include alkali metal salts oftrifluoromethanesulfonic acid, such as LiCF₃SO₃, NaCF₃SO₃ and KCF₃SO₃,alkali metal salts of perfluoroalkanesulfonic imide, such asLiN(CF₃SO₂)₂ and LiN(CF₃CF₂SO₂)₂, alkali metal salts ofhexafluorophosphoric acid, such as LiPF₆, NaPF₆ and KPF₆, perchloratealkali metal salts such as LiCl₄ and NaClO₁, tetrafluoroborates such asLiBF₄ and NaBF₄, and alkali metal salts such as LiSCN, LiAsF₆, LiI, NaI,NaAsF₆ and KI. Examples of the ammonium salt include quaternary ammoniumsalts of perchloric acid, such as tetraethylammonium perchlorate,quaternary ammonium salts of tetrafluoroboric acid, such as (C₂H₅)₄NBF₄,quaternary ammonium salts such as (C₂H )₄NPF₆, and quaternaryphosphonium salts such as (CH₃)₄P.BF₄ and (C₂H )₄P.BF₄. Among theseelectrolytes, in view of solubility in an organic solvent and ionicconductivity, LiPF₆, LiBF₄, LiAsF₆ and alkali metal salts and quaternaryammonium salts of perfluoroalkanesulfonic imide are preferred.

[0086] The ratio between the polymer component and the electrolyte saltcompounded in the solid polymer electrolyte of the present invention ispreferably such that the electrolyte salt is from 0.1 to 50% by mass,more preferably from 1 to 30% by mass, based on the weight of polymer.If the electrolyte compounded is present in a proportion of 50% by massor more, the ion transfer is greatly inhibited, whereas if theproportion thereof is less than 0.1% by mass, the absolute amount of ionis deficient and ionic conductivity is low.

[0087] (c) Organic Solvent

[0088] The solid polymer electrolyte of the present invention preferablycontains an organic solvent because ionic conductivity of the solidpolymer electrolyte is further improved. The organic solvent which canbe used is suitably a compound having good compatibility with thepolymer having a carbonate structure represented by formula (1) used inthe solid polymer electrolyte of the present invention, having a largedielectric constant, ensuring high solubility of the electrolyte salt(b), having a boiling point of 60° C. or more and being wide in anelectrochemical stability range. An organic solvent (non-aqueous organicsolvent) having a low water content is more preferred.

[0089] Examples of such a solvent include ethers such as1,2-diethoxyethane, 2-methyltetrahydrofuran, crown ether, triethyleneglycol methyl ether and tetraethylene glycol dimethyl ether; carbonicesters such as ethylene carbonate, propylene carbonate, dimethylcarbonate, diethyl carbonate, methyl ethyl carbonate and vinylenecarbonate; aliphatic esters such as methyl propionate and methylformate; aromatic nitrites such as benzonitrile and tolunitrile; amidessuch as dimethylformamide; sulfoxides such as dimethylsulfoxide;lactones such as γ-butyrolactone; sulfur compounds such as sulfolane;N-methylpyrrolidone, N-vinylpyrrolidone and phosphoric esters. Amongthese, carbonic esters, aliphatic esters and ethers are preferred, andcarbonates are more preferred. These solvents may be used individuallyor may be used as a mixed solvent by mixing two or more thereof.

[0090] As the amount of the organic solvent added is larger, the solidpolymer electrolyte obtained is further improved in ionic conductivity.Accordingly, the organic solvent content is generally large, however,curability, film forming property, or liquid holding property ormechanical strength of the solid polymer electrolyte may be impaired ifthe content is excessively large. The content is preferably from 2 to 20times, more preferably from 3 to 12 times, the mass of the polymer usedfor the solid polymer electrolyte of the present invention.

[0091] (d) Inorganic Oxide

[0092] In the foregoing, the primary components of the solid polymerelectrolyte of the present invention were described one by one, and aslong as the objects of the present invention are not inhibited, otheradditives may also be added.

[0093] For example, the electrolyte may be used as a compositeelectrolyte having added thereto inorganic oxide fine particle ofvarious types. By using the electrolyte as such, not only strength andfilm uniformity are improved, but ionic conductivity and mobility canalso be increased without impairing the effect of improving strength,because fine holes are generated between the inorganic oxide and thepolymer. In particular, when a solvent is added, a free electrolyticsolution disperses into the holes, namely, within the compositeelectrolyte.

[0094] For the inorganic oxide fine particle, those which areelectronically non-conducting and electrochemically stable are selected.Particularly, those having ionic conductivity are preferred. Specificexamples thereof include ion-conductive or electronically non-conductingceramic fine particles such as α-,β-or γ-alumina, silica, titania,magnesia and hydrotalcite.

[0095] For the purpose of increasing the amount ofelectrolyte-containing solution held in the solid polymer electrolyteand increasing ionic conductivity and mobility, the inorganic oxide fineparticle preferably has a specific surface area as large as possible.The specific surface area by BET method is preferably about 5 m²/g ormore, more preferably about 50 m²/g or more. The crystal grain size ofthe inorganic oxide fine particle is not particularly limited insofar asit can be mixed with a polymerizable composition, however, the size(average crystal grain size) is preferably from 0.01 to 20 μm, morepreferably from 0.01 to 2 μm.

[0096] The inorganic fine particle used may have various shapes such asspherical, egg-like, cubic, rectangular, cylindrical and bar-like forms.

[0097] If the amount of the inorganic fine particle added is excessivelylarge, the solid polymer electrolyte is disadvantageously reduced instrength or ionic conductivity, or becomes difficult of film formation.Accordingly, the amount of the inorganic fine particle added ispreferably 50% by mass or less, more preferably from 0.1 to 30% by mass,based on the solid polymer electrolyte.

[0098] (Production Process of Solid Polymer Electrolyte)

[0099] The solid polymer electrolyte of the present invention can beproduced by forming a polymer obtained from at least one polymerizablecompound described above or a copolymer using the polymerizable compoundas a copolymerization component into a film, polymerizing the film andcontacting it with an electrolyte salt dissolved in an organic solvent,or by preparing a polymerizable composition comprising the polymerizablecompound and other components, molding the composition, for example,into a film and polymerizing the film.

[0100] Specifically, in the latter method, at least one polymerizablecompound and at least one electrolyte salt such as alkali metal salt,quaternary ammonium salt, quaternary phosphonium salt and transitionmetal salt, are mixed and after adding and mixing another polymerizablecompound, a plasticizer, an organic solvent and/or an inorganic oxide,if desired, to prepare a polymerizable composition, the composition isformed into a film and polymerized under heating and/or irradiation ofactive rays in the presence or absence of an initiator described above,whereby a solid polymer electrolyte of the present invention isobtained. According to this method, the latitude of processing isbroadened, which is greatly advantageous in the application.

[0101] The conditions preferred for the curing of the polymerizablecomposition may be determined by selecting a thermopolymerizationinitiator according to the desired molding temperature, the kind andcurability of the polymerizable compound, and the boiling point ofsolvent, and considering the temperature necessary for halving theactive oxygen amount in the initiator (half-life temperature). Thecuring temperature and the curing rate may be determined based on thehalf-life and activation energy of the thermopolymerization initiator.For example, the temperature necessary for the half-life of 10 hours isfrom room temperature to 100° C., preferably from 40° C. to 70° C.

[0102] In the case of polymerization under irradiation of active rays,although it may vary depending on the kind of the polymerizablecompound, the polymerization may be performed, for example, byirradiating ultraviolet ray of several mW or more using an initiator,such as benzyl methyl ketal and benzophenone, or by irradiating γ ray,electron beam or the like using a solvent. The solvent may be anysolvent as long as it does not inhibit the polymerization.

[0103] The solid polymer electrolyte of the present invention may alsobe used as a composite electrolyte by compounding it with, for example,a porous polymer film of various types to improve strength, to formuniform film or to prevent short circuit between electrodes. In thiscase, the separator, after the absorption of electrolytic solution maybe reduced in ionic conductivity or deteriorated in the stabilitydepending on the kind of the polymer used, the film shape or thecompounding ratio. Therefore, the film compounded must be appropriatelyselected. Examples of the film compounded include a porous polyolefinsheet, such as polypropylene non-woven fabric and network polyolefinsheet (e.g., polyethylene-made net), polyolefin-made microporous film,such as CELLGUARD (trade name), nylon non-woven fabric, glass fiber andceramic fiber. Among these, porous polyolefin film is preferred.

[0104] The porous polymer film compounded may be sufficient if it has aporosity on the order of 10 to 95% and a thickness on the order of 1 to200 μm, however, the porosity is preferably large as much as possibleinsofar as the strength is not impaired. The porosity is preferably fromabout 40 to about 95% and the thickness is preferably from about 5 toabout 50 μm.

[0105] The compounding method is not particularly limited, however, forexample, a polymerizable composition obtained by adding and mixing atleast one polymerizable compound described above or additionally atleast one electrolyte salt and depending on the case, other components,is impregnated into a porous polymer film and the (meth)acryloyl-basedcompound is polymerized, whereby uniform compounding can be attained andthe film thickness can be easily and simply controlled.

[0106] The use of the solid polymer electrolyte of the present inventionis described in greater detail below by referring to a battery, anelectric double-layer capacitor and an electrochromic device.

[0107] (Battery and Production Process Thereof)

[0108]FIG. 1 is a schematic cross sectional view showing an example of athin-film solid battery, which is a battery according to the presentinvention. In the FIG. 1, 1 is positive electrode, 2 is porousseparator, 3 is negative electrode, 4 is collector, 5 is heat fusionpolymer film, 6 is a device case and 7 is a solid polymer electrolyte.

[0109] In the construction of the battery according to the presentinvention, when an electroactive substance (positive electroactivesubstance) having a high oxidation-reduction potential, such as metaloxide, metal sulfide, electrically conducting polymer or carbonmaterial, is used for the positive electrode 1, a battery having highvoltage and high capacity can be obtained. Among these electroactivesubstances, metal oxides, such as cobalt oxide, manganese oxide,vanadium oxide, nickel oxide and molybdenum oxide, and metal sulfides,such as molybdenum sulfide, titanium sulfide and vanadium sulfide, arepreferred because the filling density and volume capacity density can beincreased. In view of high capacity and high voltage, manganese oxide,nickel oxide and cobalt oxide are more preferred.

[0110] The method for producing the metal oxide or metal sulfide is notparticularly limited and they may be produced by a general electrolyticmethod or heating method described, for example, in Denki Kagaku(Electrochemistry), Vol. 22, page 574 (1954). In the case of a lithiumbattery, the electroactive substance is preferably used in such a statethat a Li element is intercalated (compounded) in the metal oxide ormetal sulfide, for example, in the form of Li_(x)CoO₂ and Li_(x)Mn₂O₄.The method for intercalating the Li element is not particularly limitedand, for example, a method of electrochemically intercalating a Li ionor a method described in U.S. Pat. No. 4,357,215, where a salt such asLi₂CO₃ is mixed with a metal oxide and then heat-treated, may be used.

[0111] In view of easy formation of a flexible and thin film, anelectrically conducting polymer is preferred. Examples of theelectrically conducting polymer include polyaniline, polyacetylene andderivatives thereof, poly-p-phenylene and derivatives thereof,polypyrrole and derivatives thereof, polythienylene and derivativesthereof, polypyridinediyl and derivatives thereof,polyisothianaphthenylene and derivatives thereof, polyfurylene andderivatives thereof, polyselenophene and derivatives thereof, andpolyarylene vinylene and derivatives thereof, such as poly-p-phenylenevinylene, polythienylene vinylene, polyfurylene vinylene,polynaphthenylene vinylene, polyselenophene vinylene andpolypyridinediyl vinylene. Among these, preferred are organicsolvent-soluble polymers of aniline derivatives.

[0112] Examples of the carbon material include natural graphite,artificial graphite, vapor grown graphite, petroleum coke, coal coke,pitch-type carbon, polyacene, and furalene such as C60 and C70.

[0113] The negative electroactive substance used for the negativeelectrode 3 of the battery according to the present invention ispreferably a substance having a low oxidation-reduction potential, andthe above-described alkali metal ion is used as the carrier, such asalkali metal, alkali metal alloy, carbon material, metal oxide and metalchalcogenide to attain a high-voltage and high-capacity battery. Amongthese negative electroactive substances, lithium metals and lithiumalloys, such as lithium/aluminum metal, lithium/lead alloy andlithium/antimony alloy, are more preferred in view of their lowestoxidation-reduction potential. In addition, carbon materials havingoccluded thereinto lithium ion are also preferred because a lowoxidation-reduction potential is exhibited and they are stable and safe.Examples of the material capable of occluding or releasing lithium ioninclude inorganic compounds such as tin oxide, natural graphite,artificial graphite, vapor grown graphite, petroleum coke, coal coke,pitch-type carbon, polyacene, and furalene such as C60 and C70.

[0114] For the collector 4, a material having electronic conduction,electrochemical corrosion resistance and a surface area as large aspossible is preferably used. Examples thereof include various metals andsintered body thereof, electronically conducting polymers and carbonsheet.

[0115] An example of a production process of a battery according to thepresent invention is described below.

[0116] A positive electrode 1 and a negative electrode 3 formed on acollector so that they do not come into contact with each other byinterposing a porous separator 2 therebetween are placed in an aluminumlaminate-made device case 6. Then, a polymerizable composition, whichbecomes the solid polymer electrolyte of the present invention and inwhich a thermopolymerization initiator is added, injected andimpregnated. Thereafter, the opening is sealed through a heat fusionpolymer film 5 and the polymerizable composition within the battery iscured by heating. As a result, a thin solid battery shown in FIG. 1 isobtained, where a positive electrode 1, a negative electrode 3, aseparator 2 and a solid polymer electrolyte 7 are uniformly adhered. Thedevice case is not limited to the aluminum laminate but a metal such asSUS (stainless steel), a resin such as polypropylene, a ceramic such asinsulating glass, or the like may also be used according to the end usewithout any particular limitation. The device case may have any shape,such as cylinder, box or sheet.

[0117] The battery containing the solid polymer electrolyte of thepresent invention may also be produced by a method of impregnating thepolymerizable composition into a positive electrode 1 and/or a negativeelectrode 3, curing the composition, coating further the polymerizablecomposition on either one electrode to have a uniform thickness, andcuring it by the above-described method to form a solid polymerelectrolyte film 7 on the electrode. Thereafter, another electrode isattached to the thus-formed solid polymer electrolyte film layer, whichis placed in an aluminum laminate-made device case 6, and the opening issealed through a heat fusion polymer film 5, whereby a thin solidbattery shown in FIG. 1 is obtained. In this case, if the solid polymerelectrolyte film formed on the electrode has no problem in mechanicalstrength, a porous separator is not necessary.

[0118] (Electric Double-Layer Capacitor and Production Process Thereof)

[0119] The electric double-layer capacitor of the present invention isdescribed below.

[0120] According to the present invention, an electric double-layercapacitor having high output voltage and large takeout current, andexcellent in processability, life and reliability is provided by usingthe solid polymer electrolyte of the present invention.

[0121]FIG. 2 is a schematic cross-sectional view showing an example ofan electric double-layer capacitor according to the present invention. Athin cell having a size of about 1 cm×about 1 cm and a thickness ofabout 0.5 mm, where 11 is a collector, a pair of polarizable electrodes8 and 10 are disposed in the inner side of the collector, and a porousseparator 9 compounded with a solid polymer electrolyte film 14 of thepresent invention is disposed therebetween. The numeral 13 is a devicecase and 12 is a heat fusion polymer film.

[0122] The polarizable electrodes 8 and 10 are not particularly limitedas long as they are an electrode comprising a polarizable material suchas carbon material. The polarizable electrodes preferably have a largerspecific surface area, because the electric double layer can have alarger capacity. Examples of the material include carbon black materialssuch as furnace black, thermal black (including acetylene black) andchannel black, active carbon materials such as coco shell carbon,natural graphite, artificial graphite, so-called pyrolytic graphiteproduced by the vapor phase method, polyacene, C60 and C70.

[0123] For the collector 11, a material having electronic conduction,electrochemical corrosion resistance and a specific surface area aslarge as possible is preferably used. Examples thereof include variousmetals and sintered body thereof, electronically conducting polymers andcarbon sheet.

[0124] With respect to the shape of the electric double-layer capacitor,other than the sheet form shown in FIG. 2, a coin form or a cylindricalform may be used. The cylindrical electric double-layer capacitor isproduced by rolling up a sheet laminate of polarizable electrodes and asolid polymer electrolyte into a cylindrical form, placing the roll in acylindrical tubular structure body for constructing a capacitor, andsealing it.

[0125] The kind of electrolyte salt used in the electric double-layercapacitor of the present invention is not particularly limited and acompound containing an ion intended to serve as a charge carrier may beused. However, those containing an ion capable of exhibiting a largedissociation constant in the solid polymer electrolyte and readilyforming an electric double layer with the polarizable electrodes arepreferred. Examples of such a compound include quaternary ammonium saltssuch as (CH₃)₄NBF₄ and (CH₃CH₂)₄NClO₄, transition metal salts such asAgClO₄, quaternary phosphonium salts such as (CH₃)₄PBF₄, alkali metalsalts such as LiCF₃SO₃, LiPF₆, LiI, LiBF₄, LiSCN, LiAsF₆, Li(CF₃SO₂)₂,NaCF₃SO₃, NaPF₆, NaClO₄, NaI, NaBF₄, NaAsF₆, KCF₃SO₃, KPF₆ and KI,organic acids and salts thereof such as p-toluenesulfonic acid, andinorganic acids such as hydrochloric acid and sulfuric acid. Amongthese, from the standpoint that high output voltage can be taken out andthe dissociation constant is large, quaternary ammonium salts,quaternary phosphonium salts and alkali metal salts are preferred. Amongquaternary ammonium salts, those where the substituents on nitrogen ofthe ammonium ion are different, such as (CH₃CH₂)(CH₃CH₂CH₂CH₂)₃NBF₄, arepreferred because solubility or dissociation constant in the solidpolymer electrolyte is large.

[0126] An example of a production process of an electric double-layercapacitor according to the present invention is described below.

[0127] Polarizable electrode sheets 8 and 10 coated and formed on twocollectors are placed in an aluminum laminate-made device case 13 sothat they do not come into contact with each other by interposing aporous separator 9 therebetween. Thereafter, a polymerizablecomposition, which becomes the solid polymer electrolyte of the presentinvention and in which a thermopolymerization initiator is added, isinjected and impregnated. After sealing the opening though a heat fusionpolymer film 12, the polymerizable composition within the battery iscured by heating to obtain a thin solid electric double-layer capacitorshown in FIG. 2, where polarizable electrodes 8 and 10, a porousseparator 9 and a solid polymer electrolyte 14 are uniformly adhered.The device case is not limited to the aluminum laminate but a metal suchas SUS, a resin such as polypropylene, a ceramic such as insulatingglass, or the like may also be used according to the end use without anyparticular limitation. (Electrochromic Device (ECD) and ProductionProcess Thereof)

[0128]FIG. 3 is a cross-sectional view of a thin film solid ECD havingan area of 1.5×1.5 cm, which is an example of ECD of the presentinvention. In the figure, 15 is a transparent electrically conductingelectrode, an electrochromic (EC) layer 16 is formed thereon, and asolid polymer electrolyte film 17 is disposed further thereon. Thenumeral 18 is a counter electrode, 19 is an insulating film spacer, 20is an insulating resin sealant and 21 is a lead wire.

[0129] In the construction of ECD of the present invention, the EC layer16 is sufficient if color change can reversibly take place by oxidationand reduction. Representative examples thereof include metal oxides suchas tungsten oxide, metal sulfides, viologen derivatives and polymersthereof, and electrically conducting polymers such as polyaniline,polypyrrole, polythiophene and polyisothianaphthene.

[0130] The transparent electrically conducting electrode 15 preferablyhas high electronic conductance, electrochemical corrosion resistanceand, if possible, flexibility. For this electrode, a metal such as gold,an electrically conducting oxide such as indium oxide, or anelectrically conducting polymer formed into a thin film or compounded ona transparent polymer such as polycarbonate, polymethacrylate andpolyethylene terephthalate, or on a glass sheet is used.

[0131] The counter electrode preferably has capability of reversiblytaking in or out the ion along the movement of ion of the EC layer andhas a pale color to clearly show the color change of the EC layer. Thematerial therefor varies depending on the combination with the EC layerand is not particularly limited, but examples thereof includeintercalation compounds such as metal oxide and metal sulfide,electrically conducting polymers, hydrogen-storing alloys, and alkalimetals or alloys thereof.

[0132] A production process of ECD of the present invention is describedbelow.

[0133] An EC layer 16 and a counter electrode 18 are laminated so as notto come into contact with each other using an insulating film spacer 19having a thickness as small as possible and disposed at the edge part ofthe electrode. Subsequently, a polymerizable composition, which becomesthe solid polymer electrolyte of the present invention and in which athermopolymerization initiator is added, is injected and impregnatedtherebetween. After sealing the opening with an insulting resin sealant20, the polymerizable composition within the ECD is cured by heating toobtain a solid ECD shown in FIG. 3, where an EC layer 16, a solidpolymer electrolyte 17 and a counter electrode 18 are uniformly adhered.

[0134] The viscosity can be determined using a rotary viscometer inaccordance with the method described in JIS K7117 and can be measured atvarious shear rates by changing the rotating speed of the rotaryviscometer. The change of viscosity with the passing of time can also betraced by continuously measuring the viscosity for a long period of timeat a constant rotational frequency.

[0135] The measurement apparatus used is a B-Type viscometermanufactured by Tokimeck, which is corrected with aviscometer-correction standard solution in accordance with JIS Z 8809.The measurement is performed at 25° C. in an argon atmosphere.

EXAMPLES

[0136] The present invention is described in greater detail below byreferring to the representative Examples, however, these are set forthmerely for the purpose of illustration and the present invention shouldnot be construed as being limited thereto. Unless indicated otherwiseherein, all parts, percents, ratios and the like are by mass.

Example 1 Synthesis of Polymerizable Compound (Compound 2)

[0137] Carbonate-diol (produced by Nippon Polyurethane, mass averagemolecular weight: 500) (Compound 1) and methacrylate having anisocyanate group (produced by Showa Denko K.K.) (MI) were reactedaccording to the reaction formula shown below and a polymerizablecompound (Compound 2) was obtained through the following procedure.

[0138] Specifically, 50.0 g of dehydrated Compound 1 (mass averagemolecular weight: 500, hydroxyl group value: 224 KOHmg/g, water content:30 ppm) and 32.0 g of MI were reacted in dry air at 50° C. for about 5hours while adding 0.1 g of dibutyltin dilaurate, and as a result, acolorless viscous liquid was obtained. It was found from ¹H-NMR and¹³C-NMR that Compound 1 and MI were reacted at 1:2, and since theabsorption of isocyanate group of Compound 1 disappeared from theinfrared absorption spectrum, a urethane bond was produced, and thusrevealing the production of Compound 2. The mass average molecularweight of Compound 2, determined by gel permeation chromatography (GPC),was 800 and the viscosity at 25° C. was 7,000 mPa·s.

Example 2 Synthesis of Polymerizable Compound (Compound 3)

[0139] Compound 1 and commercially available methacrylic acid (MA) werereacted according to the reaction formula shown below and apolymerizable compound (Compound 3) was obtained through the followingprocedure.

[0140] Specifically, 50.0 g of Compound 1 and 20.0 g of MA were reactedin benzene at 90° C. for about 10 hours while adding thereto 2.2 g ofp-toluenesulfonic acid (PTS). Thereafter, the reaction solution wasneutralized with an aqueous NaOH solution and then subjected to waterwashing and dehydration. As a result, a colorless viscous liquid wasobtained. It was found from ¹H-NMR and ¹³C-NMR that Compound 1 and MAwere reacted at 1:2 to produce Compound 3.

[0141] The mass average molecular weight of this compound, determined byGPC, was 650 and the viscosity at 25° C. was 230 mPa·s.

Example 3 Synthesis of Polymerizable Compound Mixture (Mixture ofCompound 5 and Compound 6)

[0142] A mixture of Compound 1 and Compound 4 (1:1 by mol) and acommercially available acrylic acid (AA) were reacted according to thereaction formula shown below and a polymerizable compound (a mixture ofCompound 5 and Compound 6) was obtained through the following procedure.

[0143] Specifically, 50.0 g of a 1:1 (by mol) mixture (mass averagemolecular weight: 500, hydroxyl group value: 180 KOHmg/g) of Compound 1and Compound 4 and 12.0 g of AA were reacted in benzene at 90° C. forabout 10 hours while adding thereto 1.5 g of PTS. Thereafter, thereaction solution was neutralized with an aqueous NaOH solution and thensubjected to water washing and dehydration. As a result, a colorlessviscous liquid was obtained. It was found from ¹H-NMR and ¹³C-NMR thatCompound 1, Compound 4 and AA were reacted at 1:1:3 to produce a mixtureof Compound 5 and Compound 6.

[0144] The mass average molecular weight of this compound, determined byGPC, was 600 and the viscosity at 25° C. was 70 mPa·s.

Example 4 Synthesis of Polymerizable Compound Mixture (Mixture ofCompound 2 and Compound 7)

[0145] A mixture of Compound 1 and Compound 4 (1:1 by mol) and MI(produced by Showa Denko K.K.) were reacted according to the reactionformula shown below and a polymerizable compound (a mixture of Compound2 and Compound 7) was obtained through the following procedure.

[0146] Specifically, 50.0 g of a dehydrated 1:1 (by mol) mixture ofCompound 1 and Compound 4 and 25.0 g of MI were reacted in dry air at50° C. for about 5 hours while adding thereto 0.08 g of dibutyltindilaurate, and as a result, a colorless viscous liquid was obtained.

[0147] It was found from ¹H-NMR and ¹³C-NMR that Compound 1, Compound 4and MI were reacted at 1:1:3 to produce a mixture of Compound 2 andCompound 7.

[0148] The mass average molecular weight of this compound, determined byGPC, was 700 and the viscosity at 25° C. was 360 mPa·s.

Example 5

[0149] Preparation of Polymerizable Composition A

[0150] 1.0 g of Compound 2 synthesized in Example 1, 7.0 g of diethylcarbonate (DEC), 2.0 g of ethylene carbonate (EC), 1.0 g of LiPF₆, 40 mgof 2,4-diphenyl-4-methyl-1-pentene (NOFMER MSD, a trade name, producedby NOF Corp.) as a polymerization retarder and 50 mg of t-hexylperoxypivalate (PERHEXYL PV, a trade name, produced by NOF Corp.) as athermopolymerization initiator were thoroughly mixed in an argonatmosphere to obtain Polymerizable Composition A for a solid polymerelectrolyte. This composition had an initial viscosity of 5.8 mPa·s (at25° C.). When 1 g of this polymerizable composition was heated at 60° C.for 60 minutes in an argon atmosphere, the composition was cured and asolid polymer electrolyte resulting from the polymerization of Compound2 was obtained. This cured product had a residual double bond contentlower than the detectable limit in the infrared spectrum and an ionicconductivity of 4.7 mS/cm (at 25° C.).

[0151] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 15 hours and the composition as a whole lost fluidity andsolidified.

Example 6 Preparation of Polymerizable Composition B

[0152] Polymerizable Composition B for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g ofCompound 3 synthesized in Example 2 was used in place of 1.0 g ofCompound 2 and the amount of polymerization retarder NOFMER MSD(produced by NOF Corp.) was changed from 40 mg to 10 mg. Thiscomposition had an initial viscosity of 4.7 mPa·s (at 25° C.). When 1 gof this polymerizable composition was heated at 80° C. for 60 minutes inan argon atmosphere, the composition was cured and a solid polymerelectrolyte resulting from the polymerization of Compound 3 wasobtained. This cured product had a residual double bond content lowerthan the detectable limit in the infrared spectrum and an ionicconductivity of 3.8 mS/cm (at 25° C.).

[0153] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 25 hours and the composition as a whole lost fluidity andsolidified.

Example 7 Preparation of Polymerizable Composition C

[0154] Polymerizable Composition C for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g of amixture of Compound 5 and Compound 6 synthesized in Example 3 was usedin place of 1.0 g of Compound 2 and the amount of polymerizationretarder NOFMER MSD (produced by NOF Corp.) was changed from 40 mg to 10mg. This composition had an initial viscosity of 4.2 mPa·s (at 25° C.).When 1 g of this polymerizable composition was heated at 80° C. for 60minutes in an argon atmosphere, the composition was cured and a solidpolymer electrolyte resulting from the copolymerization of Compound 5and Compound 6 was obtained. This cured product had a residual doublebond content lower than the detectable limit in the infrared spectrumand an ionic conductivity of 4.0 mS/cm (at 25° C.).

[0155] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 30 hours and the composition as a whole lost fluidity andsolidified.

Example 8 Preparation of Polymerizable Composition D

[0156] Polymerizable Composition D for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g of amixture of Compound 2 and Compound 7 synthesized in Example 4 was usedin place of 1.0 g of Compound 2. This composition had an initialviscosity of 4.8 mPa·s (at 25° C.). When 1 g of this polymerizablecomposition was heated at 60° C. for 60 minutes in an argon atmosphere,the composition was cured and a solid polymer electrolyte resulting fromthe copolymerization of Compound 2 and Compound 7 was obtained. Thiscured product had a residual double bond content lower than thedetectable limit in the infrared spectrum and an ionic conductivity of4.8 mS/cm (at 25° C.).

[0157] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 15 hours and the composition as a whole lost fluidity andsolidified.

Example 9 Synthesis of Polymerizable Compound (Compound 9)

[0158] Carbonate-diol (produced by Nippon Polyurethane, mass averagemolecular weight: 500) (Compound 8) and MI (produced by Showa DenkoK.K.) were reacted according to the reaction formula shown below and apolymerizable compound (Compound 9) was obtained through the followingprocedure.

[0159] Specifically, 50.0 g of dehydrated Compound 8 (mass averagemolecular weight: 500, hydroxyl group value: 224 KOHmg/g, water content:30 ppm) and 32.0 g of MI were reacted in dry air at 50° C. for about 5hours while adding thereto 0.1 g of dibutyltin dilaurate. As a result, acolorless viscous liquid was obtained. It was found from ¹H-NMR and¹³C-NMR that Compound 8 and MI were reacted at 1:2 and since theabsorption of isocyanate group of Compound 8 disappeared from theinfrared absorption spectrum, a urethane bond was produced, and thusrevealing the production of Compound 9. The mass average molecularweight of Compound 9, determined by GPC (gel permeation chromatography),was 800 and the viscosity at 25° C. was 3,000 mPa·s.

Example 10 Synthesis of Polymerizable Compound (Compound 10)

[0160] Compound 8 and commercially available AA were reacted accordingto the reaction formula shown below and a polymerizable compound(Compound 10) was obtained through the following procedure.

[0161] Specifically, 50.0 g of Compound 8 and 17.0 g of AA were reactedin benzene at 90° C. for about 10 hours while adding thereto 2.2 g ofPTS. Thereafter, the reaction solution was extracted with chloroform anddehydrated, and as a result, a colorless viscous liquid was obtained. Itwas found from ¹H-NMR and ¹³C-NMR that Compound 8 and AA were reacted at1:2 to produce Compound 10.

[0162] The mass average molecular weight of this compound, determined byGPC, was 650 and the viscosity at 25° C. was 150 mPa·s.

Example 11 Preparation of Polymerizable Composition E

[0163] Polymerizable Composition E for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g ofCompound 9 synthesized in Example 9 was used in place of 1.0 g ofCompound 2. This composition had an initial viscosity of 5.1 mPa·s (at25° C.). When 1 g of this polymerizable composition was heated at 60° C.for 60 minutes in an argon atmosphere, the composition was cured and asolid polymer electrolyte resulting from the polymerization of Compound9 was obtained. This cured product had a residual double bond contentlower than the detectable limit in the infrared spectrum and an ionicconductivity of 3.8 mS/cm (at 25° C.).

[0164] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 25 hours and the composition as a whole lost fluidity andsolidified.

Example 12 Preparation of Polymerizable Composition F

[0165] Polymerizable Composition F for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g ofCompound 10 synthesized in Example 10 was used in place of 1.0 g ofCompound 2 and the amount of polymerization retarder NOFMER MSD (NOFCorp.) was changed from 40 mg to 5 mg. This composition had an initialviscosity of 4.4 mPa·s (at 25° C.). When 1 g of this polymerizablecomposition was heated at 80° C. for 60 minutes in an argon atmosphere,the composition was cured and a solid polymer electrolyte resulting fromthe polymerization of Compound 10 was obtained. This cured product had aresidual double bond content lower than the detectable limit in theinfrared spectrum and an ionic conductivity of 3.7 mS/cm (at 25° C.).

[0166] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 30 hours and the composition as a whole lost fluidity andsolidified.

Comparative Example 1 Synthesis of Polymerizable Compound (Compound 12)

[0167] Carbonate-diol (produced by Nippon Polyurethane K.K., massaverage molecular weight: 500) (Compound 11) and MI (produced by ShowaDenko K.K.) were reacted according to the reaction formula shown belowand a polymerizable compound (Compound 12) was obtained through thefollowing procedure.

[0168] Specifically, 50.0 g of dehydrated Compound 11 (mass averagemolecular weight: 500, hydroxyl group value: 224 KOHmg/g, water content:30 ppm) and 32.0 g of MI were reacted in dry air at 50° C. for about 5hours while adding thereto 0.1 g of dibutyltin dilaurate. As a result, acolorless viscous liquid was obtained. It was found from ¹H-NMR and¹³C-NMR that Compound 11 and MI were reacted at 1:2 and since theabsorption of isocyanate group of Compound 11 disappeared from theinfrared absorption spectrum, a urethane bond was produced, and thusrevealing the production of Compound 12. The mass average molecularweight of Compound 12, determined by GPC, was 800. This compound wassolid at 25° C. and liquefied at 45° C. and the viscosity thereof was2,000 mPa·s.

Comparative Example 2 Synthesis of Polymerizable Compound (Compound 13)

[0169] Compound 11 and commercially available acrylic acid (AA) werereacted according to the reaction formula shown below and apolymerizable compound (Compound 13) was obtained through the followingprocedure.

[0170] Specifically, 50.0 g of Compound 11 and 17.0 g of AA were reactedin benzene at 90° C. for about 10 hours while adding thereto 2.2 g ofPTS. Thereafter, the reaction solution was washed with an aqueous NaOHsolution and then dehydrated, and as a result, a colorless viscousliquid was obtained. It was found from ¹H-NMR and ¹³C-NMR that Compound1 and AA were reacted at 1:2 to produce Compound 13.

[0171] The mass average molecular weight of this compound, determined byGPC, was 650. This compound was solid at 25° C. and liquefied at 45° C.and the viscosity thereof was 220 mPa·s.

Comparative Example 3 Synthesis of Polymerizable Compound (Compound 15)

[0172] Carbonate-diol (produced by Nippon Polyurethane K.K., massaverage molecular weight: 2,000) (Compound 14) and MI (produced by ShowaDenko K.K.) were reacted according to the reaction formula shown belowand a polymerizable compound (Compound 15) was obtained through thefollowing procedure.

[0173] Specifically, 50.0 g of dehydrated Compound 14 (mass averagemolecular weight: 2,000, hydroxyl group value: 56 KOHmg/g, watercontent: 30 ppm) and 8.0 g of MI were reacted in dry air at 50° C. forabout 5 hours while adding thereto 0.02 g of dibutyltin dilaurate, andas a result, a colorless viscous liquid was obtained. It was found from¹H-NMR and ¹³C-NMR that Compound 14 and MI were reacted at 1:2 and sincethe absorption of isocyanate group of Compound 14 disappeared from theinfrared spectrum, a urethane bond was produced, and thus revealing theproduction of Compound 15. The mass average molecular weight of Compound2, determined by GPC, was 2,300 and the viscosity at 25° C. was 100,000mPa·s.

Comparative Example 4 Synthesis of Polymerizable Compound (Compound 16)

[0174] Compound 14 and commercially available AA were reacted accordingto the reaction formula shown below and a polymerizable compound(Compound 16) was obtained through the following procedure.

[0175] Specifically, 50.0 g of Compound 14 and 4.0 g of AA were reactedin benzene at 90° C. for about 5 hours while adding thereto 0.5 g ofPTS. Thereafter, the reaction solution was extracted with chloroform anddehydrated, and as a result, a colorless viscous liquid was obtained. Itwas found from ¹H-NMR and ³C-NMR that Compound 14 and AA were reacted at1:2 to produce Compound 16.

[0176] The mass average molecular weight of this compound, determined byGPC, was 2,100 and the viscosity at 25° C. was 2,000 mPa·s.

Comparative Example 5 Preparation of Polymerizable Composition G

[0177] Polymerizable Composition G for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g ofCompound 12 synthesized in Comparative Example 1 was used in place of1.0 g of Compound 2. This composition had an initial viscosity of 6.7mPa·s (at 25° C.). When 1 g of this polymerizable composition was heatedat 60° C. for 60 minutes in an argon atmosphere, the composition wascured and a solid polymer electrolyte resultant from the polymerizationof Compound 12 was obtained. This cured product had a residual doublebond content lower than the detectable limit in the infrared spectrumand an ionic conductivity of 4.2 mS/cm (at 25° C.).

[0178] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 12 hours and the composition as a whole lost fluidity andsolidified.

Comparative Example 6 Preparation of Polymerizable Composition H

[0179] Polymerizable Composition H for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g ofCompound 13 synthesized in Comparative Example 2 was used in place of1.0 g of Compound 2 and the amount of polymerization retarder NOFMER MSD(NOF Corp.) was changed from 40 mg to 5 mg. This composition had aninitial viscosity of 4.4 mPa·s (at 25° C.). When 1 g of thispolymerizable composition was heated at 80° C. for 60 minutes in anargon atmosphere, the composition was cured and a solid polymerelectrolyte resulting from the polymerization of Compound 13 wasobtained. This cured product had a residual double bond content lowerthan the detectable limit in the infrared spectrum and an ionicconductivity of 3.4 mS/cm (at 25° C.).

[0180] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 30 hours and the composition as a whole lost fluidity andsolidified.

Comparative Example 7 Preparation of Polymerizable Composition I

[0181] Polymerizable Composition I for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g ofCompound 15 synthesized in Comparative Example 3 was used in place of1.0 g of Compound 2. This composition had an initial viscosity of 7.8mPa·s (at 25° C.). When 1 g of this polymerizable composition was heatedat 60° C. for 60 minutes in an argon atmosphere, the composition wascured and a solid polymer electrolyte resulting from the polymerizationof Compound 15 was obtained. This cured product had a residual doublebond content lower than the detectable limit in the infrared spectrumand an ionic conductivity of 4.3 mS/cm (at 25° C.).

[0182] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 30 hours and the composition as a whole lost fluidity andsolidified.

Comparative Example 8 Preparation of Polymerizable Composition J

[0183] Polymerizable Composition J for solid polymer electrolyte wasobtained in the same manner as in Example 5, except that 1.0 g ofCompound 16 synthesized in Comparative Example 4 was used in place of1.0 g of Compound 2 and the amount of polymerization retarder NOFMER MSD(NOF Corp.) was changed from 40 mg to 5 mg. This composition had aninitial viscosity of 5.7 mPa·s (at 25° C.). When 1 g of thispolymerizable composition was heated at 80° C. for 60 minutes in anargon atmosphere, the composition was cured and a solid polymerelectrolyte resulting from the polymerization of Compound 16 wasobtained. This cured product had a residual double bond content lowerthan the detectable limit in the infrared spectrum and an ionicconductivity of 3.2 mS/cm (at 25° C.).

[0184] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 30 hours and the composition as a whole lost fluidity andsolidified.

Example 13 Production of Lithium Cobaltate Positive Electrode

[0185] 11 g of Li₂CO₃ and 24 g of Co₃O₄ were thoroughly mixed and themixture was heated at 800° C. for 24 hours in an oxygen atmosphere andpulverized to obtain LiCoO₂ powder. This LiCoO₂ powder, acetylene blackand polyvinylidene fluoride were mixed at a mass ratio of 8:1:1 andthereto, an excess N-methylpyrrolidone solution was added to obtain agel composition.

[0186] This composition was coated on an aluminum foil of about 50 μmand formed under pressure to a thickness of about 75 μm to obtain alithium cobaltate positive electrode sheet. This sheet was cut into a 36mm square and used as the positive electrode for battery.

Example 14 Production of Graphite Negative Electrode

[0187] To a 8.6:0.4:1.0 (by mass) mixture of MCMB graphite (produced byOsaka Gas Co., Ltd.), vapor grown graphite fiber (produced by ShowaDenko K.K., average fiber diameter: 0.3 μm, average fiber length: 2.0μm, a product heat-treated at 2,700° C.) and polyvinylidene fluoride, anexcess N-methylpyrrolidone solution was added to obtain a gelcomposition. This composition was coated on a copper foil of about 50 μmand formed under pressure to a thickness of about 85 μm to obtain agraphite negative electrode sheet. This sheet was cut into a 40 mmsquare and used as the negative electrode for battery.

Example 15 Production of Solid Li Ion Secondary Battery

[0188] Within a glove box in an argon atmosphere, a sheet-like graphitenegative electrode similar to the sheet produced in Example 14, asheet-like lithium cobaltate positive electrode similar to the sheetproduced in Example 13 and a 42 mm-square polyolefin microporous filmwere left standing in Polymerizable Composition A prepared in Example 5and impregnated with the composition. Thereafter, the positive electrodeand the negative electrode were laminated through the microporous filmso that the microporous film slightly protruded from the edges (foursides) of the positive and negative electrodes. These were placed in abag (armor body) made of a Polypropylene (PP)/Al/Polyethyleneterephthalate (PET) three-layer laminate and after heat-fusing to sealthe bag while applying a pressure from both surfaces using 1.1 mm-thickglass plates, the polymerizable composition was cured by heating it at60° C. for 120 minutes to obtain a solid battery in which solid polymerelectrolyte is compounded in electrodes and separator.

[0189] This battery was charged and discharged with a working voltage of2.75 to 4.2 V and an electric current of 7 mA at 25° C. and −20° C., andas a result, the maximum discharge capacity was 32.5 mAh and 18.8 mAh,respectively. At this time, the charge-discharge coulombic efficiencywas almost 100%.

[0190] The battery was repeatedly charged and discharged at 25° C., aworking voltage of 2.75 to 4.2 V, a charge current of 7 mA and adischarge current of 35 mA. As a result, the maximum discharge capacitywas 30.5 mAh and, even after working in excess of 300 cycles, thecapacity was 70% or more of the initial capacity and not extremelyreduced.

Examples 16 to 20 Production of Solid Li Ion Secondary Battery

[0191] Solid batteries in which solid polymer electrolyte withinelectrodes and separator was compounded were obtained in the same manneras in Example 15, except that Polymerizable Composition B, C, D, E or Fprepared in Example 6, 7, 8, 11 or 12, respectively, were used in placeof Polymerizable Composition A used in Example 15. However, the timeperiod for allowing the polymerizable composition to impregnate intopositive and negative electrodes and separator was selected to ensurethe impregnation according to the viscosity of each composition.

[0192] These batteries were each charged and discharged with a workingvoltage of 2.75 to 4.2 V and an electric current of 7 mA at 25° C. and−20° C., and found to have maximum discharge capacity andcharge-discharge coulombic efficiency shown in Table 1.

[0193] Also, each battery was repeatedly charged and discharged at 25°C., a working voltage of 2.75 to 4.2 V, a charge current of 7 mA and adischarge current of 35 mA, and found to have maximum discharge capacityand capacity maintenance percentage (ratio to the initial capacity)after 300 cycles shown in Table 1.

Comparative Examples 9 to 12 Production of Solid Li Ion SecondaryBattery

[0194] Solid batteries in which the polymerizable composition was curedand in which a solid polymer electrolyte within electrodes and separatorwas compounded, were obtained in the same manner as in Example 15,except that Polymerizable Composition G, H, I or J prepared inComparative Example 5, 6, 7 or 8, respectively, were used in place ofPolymerizable Composition A used in Example 15. However, the time periodfor allowing the polymerizable composition to impregnate into positiveand negative electrodes and separator was selected to ensure theimpregnation according to the viscosity of each composition.

[0195] These batteries each was charged and discharged with a workingvoltage of 2.75 to 4.2 V and an electric current of 7 mA at 25° C. and20° C., and found to have maximum discharge capacity shown in Table 2.

[0196] Also, each battery was repeatedly charged and discharged at 25°C., a working voltage of 2.75 to 4.2 V, a charge current of 7 mA and adischarge current of 35 mA, and found to have maximum discharge capacityand capacity maintenance percentage (ratio to the initial capacity)after 300 cycles shown in Table 2. TABLE 1 Performance of Solid LiIon,Secondary Battery Capacity (mAh) at Maximum Discharge 25° C. · 35 mACapacity at 7 mA Maximum Capacity Impregnation (mAh) Discharge After 300Example Time (hr) 25° C. −20° C. Capacity Cycles 15 6 32.5 16.5 30.521.4(70%) 16 4 32.5 18.0 30.0 22.5(75%) 17 3 32.5 18.5 30.0 21.0(70%) 185 32.5 17.0 31.0 22.3(72%) 19 5 32.5 17.0 31.0 21.0(68%) 20 4 32.5 18.029.5 22.1(75%)

[0197] TABLE 2 Performance of Solid Li Ion Secondary Battery Capacity(mAh) at Maximum 25° C. · 35 mA Discharge Capacity Maximum CapacityComparative Impregnation at 7 mA (mAh) Discharge After 300 Example Time(hr) 25° C. −20° C. Capacity Cycles  9 10 30.0 12.0 29.5 19.2(65%) 10  432.5 14.0 26.0 18.2(70%) 11 15 28.0 12.5 27.0 16.2(60%) 12  5 30.0 13.525.5 15.3(60%)

Example 21 Preparation of Polymerizable Composition K

[0198] 1.0 g a mixture (1:1 by mol) of Compound 5 and Compound 6synthesized in Example 3, 9.0 g of propylene carbonate (PC), 2.0 g oftriethylmethylammonium tetrafluoroborate (TEMABF₄), 20 mg ofpolymerization retarder NOFMER MSD (produced by NOF Corp.) and 50 mg ofthermopolymerization initiator PERHEXYL PV (produced by NOF Corp.) werethoroughly mixed in an argon atmosphere to obtain PolymerizableComposition K for a solid polymer electrolyte. This composition had aninitial viscosity of 6.3 mPa·s (at 25° C.). When 1 g of thispolymerizable composition was heated at 80° C. for 60 minutes in anargon atmosphere, the composition was cured and a solid polymerelectrolyte resulting from the copolymerization of Compound 5 andCompound 6 was obtained. This cured product had a residual double bondcontent lower than the detectable limit in the infrared spectrum and anionic conductivity of 14.1 mS/cm (at 25° C.).

[0199] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 20 hours and the composition as a whole lost fluidity andsolidified.

Example 22 Production of Active Carbon Electrode

[0200] An excess N-methylpyrrolidone solution was added to a 8.6:0.4:1.0(by mass) mixture of steam reactivation active carbon (specific surfacearea: 2,230 m²/g, average particle size: 7 μm, pore volume: 0.7 ml/g) asa phenol resin calcined product, vapor grown graphite fiber (produced byShowa Denko K.K., average fiber diameter: 0.3 μm, average fiber length:2.0 μm, a product heat-treated at 2,700° C.) and polyvinylidenefluoride, to obtain a gel composition. This composition was coated on analuminum foil of about 25 μm and formed under pressure to a thickness ofabout 150 μm to obtain an active carbon electrode sheet. This sheet wascut into a 10 mm square and vacuum dried at 100° C. for 10 hours toobtain an active carbon electrode (230.0 mg) for electric double-layercapacitor.

Example 23 Production of Solid Electric Double-layer Capacitor

[0201] Within a glove box in an argon atmosphere, two sheets of activecarbon electrodes (230.0 mg, 40 mm square) produced in Example 22 and aTeflon-made microporous film separator (42 mm square, 25 μm thickness,produced by Mitsui FLOROCHEMICAL) were left standing in PolymerizableComposition K prepared in Example 21 at room temperature for 8 hours andimpregnated with the composition. Thereafter, these two sheets ofelectrodes were laminated with an interposition of microporous filmseparator so that the microporous film slightly protruded from the edges(four sides) of two sheets of electrodes. These were placed in a bag(armor body) made of a PP/Al/PET three-layer laminate and afterheat-fusing to seal the bag while applying a pressure from both surfacesusing 1.1 mm-thick glass plates, the polymerizable composition was curedby heating it at 60° C. for 120 minutes to obtain a solid electricdouble-layer capacitor, where the solid polymer electrolyte wascompounded in electrodes and separator.

[0202] This capacitor was charged and discharged at 25° C. and −20° C.,a working voltage of 0 to 2.5 V and an electric current of 7 mA, and asa result, the maximum capacitance was 9.1 F and 6.6 F, respectively.Furthermore, the capacitor was charged and discharged at 25° C. and 14mA, and as a result, the maximum capacitance was 8.9 F. Thereafter, thecharge and discharge were repeated 100 times but the capacitance wasscarcely changed.

Example 24 Preparation of Polymerizable Composition L

[0203] 1.0 g of a mixture (1:1 by mol) of Compound 5 and Compound 6synthesized in Example 3, 9.0 g of propylene carbonate (PC), 1.0 g ofLiBF₄, 5 mg of polymerization retarder NOFMER MSD (produced by NOFCorp.) and 50 mg of thermopolymerization initiator PERHEXYL PV (producedby NOF Corp.) were thoroughly mixed in an argon atmosphere to obtainPolymerizable Composition L for a solid polymer electrolyte. Thiscomposition had an initial viscosity of 4.5 mPa·s (at 25° C.). When 1 gof this polymerizable composition was heated at 80° C. for 60 minutes inan argon atmosphere, the composition was cured and a solid polymerelectrolyte resulting from the copolymerization of Compound 5 andCompound 6 was obtained. This cured product had a residual double bondcontent lower than the detectable limit in the infrared spectrum and anionic conductivity of 5.0 mS/cm (at 25° C.).

[0204] Also, when 1 g of the thus-prepared polymerizable composition wasleft standing at 25° C. in an argon atmosphere, the viscosity abruptlyelevated after 25 hours and the composition as a whole lost fluidity andsolidified.

Example 25 Manufacture of WO₃-made EC Electrode

[0205] On an electrode comprising an ITO glass (produced by MatsuzakiShinku K.K.) cut into 1.2×1.2 cm with the edges being covered to have anITO exposed area of 1×1 cm, WO₃ was vacuum deposited using tantalum boatmember by a resistance heating method at 10⁻⁵ to 10⁻⁶ Torr (1.33×10⁻³ to1.33×10⁻⁴ Pa) to obtain WO₃ electrode. The obtained WO₃ film had athickness of about 1,000 Å (1×10⁻⁷ m) and a density of about 5 g/cm³.

Example 26 Manufacture of Polyaniline (PAn)-made EC Electrode

[0206] On an electrode comprising ITO glass (produced by MatsuzakiShinku K.K.) cut into 1.2×1.2 cm, potential scanning was repeated at ascanning speed of 0.2 V/sec in the range from −0.2 to 0.8 V vs. SCEusing an aqueous 1 mol hydrochloric acid solution containing 0.5 molaniline as the electrolytic solution and an ITO glass of 2×2 cm as thecounter electrode, whereby a doped green electrolytically polymerizedPAn film of about 5,000 Å thickness was manufactured. This film wasthoroughly washed with aqueous ammonia and distilled water, reduced withhydrazine and vacuum dried at 100° C. for about 3 hours to obtain anundoped white PAn electrode.

Example 27 Manufacture of Electrochromic Device (ECD)

[0207] Within a glove box in an argon atmosphere, the edge part withinabout 1 mm around of the PAn electrode (1.2 cm-square) produced inExample 26 was coated with a polyimide film spacer. Thereafter, thepolymerizable composition prepared in Example 24 was coated on the PAnelectrode and WO₃ electrode produced in Example 25 was stacked thereonand heated at 60° C. for 120 minutes. By sealing the edge part with anepoxy resin, an ECD shown in FIG. 3 was manufactured. This ECD wasdriven with an injected electricity of 6 mC/cm² at a working voltage of−2 to 2 V, and as a result, electrochromism of deep blue/pale blue wasexhibited and the response seed was about 100 msec. Even when thedriving was repeated 200 times under these conditions, the color toneand response speed were not changed.

[0208] The highly ion conductive solid polymer electrolyte comprising apolymer having a carbonate group as a main component and an electrolytesalt of the present invention has high ionic conductivity, excellentelectrochemical stability and good durability. By introducing a branchedchain, excellent processability and compounding property with othermaterials are ensured when the solid polymer electrolyte of the presentinvention is used as an electrochemical device. In particular, when thecarbonate-based solid polymer electrolyte of the present invention isobtained by polymerizing a low molecular weight polymerizable compoundhaving a branched carbonate structure, compounding with variousmaterials can be performed before polymerization, thereby improvingprocessability and compounding property.

[0209] The battery, electric double-layer capacitor and ECD using thesolid polymer electrolyte of the present invention are free from fearsof liquid leakage, and are favored with excellent reliability and safetyover a long period of time and has wide freeness in shape such as thintype.

[0210] The battery of the present invention uses the above-describedsolid polymer electrolyte and therefore, can be easily formed into afilm. Also, the battery can be easily and simply compounded withrespective elements such as positive electrode and/or negative electrodeand/or separator so that the battery can work with high capacity andhigh current, and ensures long life and high reliability.

[0211] The battery of the present invention can work with high capacityand high current as a solid battery or can ensure good cycle propertyand excellent safety and reliability so that the battery can be used asa power source for electrical products, such as main power source orbackup power source of portable appliances, or as a large-sized powersource for electric cars or road leveling. Furthermore, the battery canbe easily formed into a thin film and therefore, can be used as a paperbattery for an identification card or the like.

[0212] The electric double-layer capacitor of the present invention usesthe above-described solid polymer electrolyte so that the capacitor canhave high output voltage, large takeout current, good processability,long life and excellent reliability.

[0213] Furthermore, the electric double-layer capacitor of the presentinvention is a solid electric double-layer capacitor capable of workingwith high voltage, high capacitance and high current, and ensuring goodcycle property, excellent safety and high reliability compared withconventional solid electric double-layer capacitors. Accordingly, thecapacitor can be used not only as a backup power source, but also as apower source for various electrical products by using it in combinationwith a compact battery. In addition, the electric double-layer capacitorof the present invention has excellent processability such as formationinto thin film and therefore, can be applied to uses other than those ofconventional solid-state electric double-layer capacitors.

[0214] While the invention has been described in detail and withreference to specific embodiments thereof, it will be apparent to oneskilled in the art that various changes and modifications can be madetherein without departing from the spirit and scope thereof.

What is claimed is:
 1. A solid polymer electrolyte comprising a polymercompound having a branched carbonate structure represented by formula(1) as a partial structure and at least one electrolyte salt:

wherein each R¹ and R² independently represents a hydrogen atom, alinear, branched or cyclic alkyl group having from 1 to 10 carbon atoms,a linear, branched or cyclic alkoxy group having from 1 to 10 carbonatoms or a linear, branched or cyclic alkoxyalkyl group having from 1 to10 carbon atoms, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, and each R¹ and R² and each value of m and n can bethe same or different, provided that R¹ or R² present in pluralitywithin the same molecule are not a hydrogen atom at the same time.
 2. Asolid polymer electrolyte comprising a polymer compound having abranched carbonate structure represented by formula (2) as a partialstructure and at least one electrolyte salt:

wherein R³ represents a hydrogen atom, a linear, branched or cyclicalkyl group having from 1 to 10 carbon atoms, a linear, branched orcyclic alkoxy group having from 1 to 10 carbon atoms or a linear,branched or cyclic alkoxyalkyl group having from 1 to 10 carbon atoms, mrepresents an integer of 3 to 10, n represents an integer of 1 to 500,and each R³ and each value of m and n can be the same or different,provided that R³ present in plurality within the same molecule are not ahydrogen atom at the same time.
 3. A solid polymer electrolyte which isa polymer of a polymerizable compound having a branched carbonatestructure described in claim 1 or 2 and a polymerizable functional grouprepresented by the following formula (3) and/or (4):

wherein R⁴ represents a hydrogen atom or a linear, branched or cyclicalkyl group having from 1 to 10 carbon atoms, R⁶ represents a hydrogenatom, a linear, branched or cyclic alkyl group having from 1 to 10carbon atoms, a linear, branched or cyclic alkoxy group having from 1 to10 carbon atoms or a linear, branched or cyclic alkoxyalkyl group havingfrom 1 to 10 carbon atoms, R⁵ represents a divalent group which cancontain a heteroatom and can have a linear, branched or cyclicstructure, and x represents 0 or 1, provided that R⁴, R⁵, R⁶ or xpresent in plurality within the same molecule can be the same ordifferent.
 4. The solid polymer electrolyte as claimed in claim 3,wherein the polymerizable compound has a mass average molecular weightof about 100 to about 3,000.
 5. The solid polymer electrolyte as claimedin claim 3, wherein the polymerizable compound is almost liquid at roomtemperature and a viscosity thereof is about 5,000 mPa·S (25° C.) orless.
 6. The solid polymer electrolyte as claimed in claim 1 or 2, whichfurther comprises at least one organic solvent.
 7. A polymerizablecomposition for a solid polymer electrolyte, comprising at least onepolymerizable compound claimed in claim 3, and at least one electrolytesalt.
 8. The polymerizable composition for a solid polymer electrolyteas claimed in claim 7, further comprising at least one organic solvent.9. The polymerizable composition for a solid polymer electrolyte asclaimed in claim 8, wherein a viscosity is about 6.0 mPa·S (25° C.) orless.
 10. A solid polymer electrolyte obtained by polymerizing thepolymerizable composition claimed in claim
 7. 11. A solid polymerelectrolyte obtained by polymerizing the polymerizable compositionclaimed in claim
 8. 12. A solid polymer electrolyte obtained bypolymerizing the polymerizable composition claimed in claim
 9. 13. Thesolid polymer electrolyte as claimed in claim 1 or 2, wherein theelectrolyte salt is at least one selected from the group consisting ofan alkali metal salt, a quaternary ammonium salt and a quaternaryphosphonium salt.
 14. The polymerizable composition for a solid polymerelectrolyte as claimed in claim 7, wherein the electrolyte salt is atleast one selected from the group consisting of an alkali metal salt, aquaternary ammonium salt and a quaternary phosphonium salt.
 15. Thesolid polymer electrolyte as claimed in claim 6, wherein the organicsolvent is at least one selected from the group consisting ofcarbonates, aliphatic esters, ethers, lactones, sulfoxides and amides.16. The polymerizable composition for solid polymer electrolytes asclaimed in claim 8, wherein the organic solvent is at least one selectedfrom the group consisting of carbonates, aliphatic esters, ethers,lactones, sulfoxides and amides.
 17. A battery comprising a solidpolymer electrolyte as claimed in claim 1, a positive electrode and anegative electrode.
 18. The battery as claimed in claim 17, which is alithium primary or lithium secondary battery comprising at least oneelectrolyte salt selected from the group consisting of LiPF₆, LiBF₄,LiAsF₆ and LiN(A—SO₂)₂, wherein A represents a perfluoroalkyl grouphaving from 1 to 10 carbon atoms.
 19. An electric double-layer capacitorcomprising a solid polymer electrolyte as claimed in claim 1 or 2, and apair of polarizable electrodes.
 20. An electrochromic device comprisinga solid polymer electrolyte as claimed in claim 1 or 2, and anelectrochromic layer.
 21. A polymerizable compound represented byformula (5):

wherein each R¹ and R² independently represents a hydrogen atom, alinear, branched or cyclic alkyl group having from 1 to 10 carbon atoms,a linear, branched or cyclic alkoxy group having from 1 to 10 carbonatoms or a linear, branched or cyclic alkoxyalkyl group having from 1 to10 carbon atoms, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, R⁴ represents hydrogen or a linear, branched orcyclic alkyl group having from 1 to 10 carbon atoms, R⁷ represents achained, branched and/or cyclic organic group having from 1 to 30 carbonatoms, which can contain a heteroatom and/or an unsaturated bond, andeach R¹, R², R⁴, and R⁷ and each value of m and n, provided that R¹ orR² present in plurality within the same molecule are not a hydrogen atomat the same time.
 22. A polymerizable compound represented by formula(6):

wherein each R¹ and R² independently represents a hydrogen atom, alinear, branched or cyclic alkyl group having from 1 to 10 carbon atoms,a linear, branched or cyclic alkoxy group having from 1 to 10 carbonatoms or a linear, branched or cyclic alkoxyalkyl group having from 1 to10 carbon atoms, m represents an integer of 3 to 10, n represents aninteger of 1 to 500, x represents 0 or 1, R⁴ represents a hydrogen atomor a linear, branched or cyclic alkyl group having from 1 to 10 carbonatoms, R⁷ represents a chained, branched and/or cyclic organic grouphaving from 1 to 30 carbon atoms, which can contain a heteroatom and/oran unsaturated bond, R⁶ represents a hydrogen atom, a linear, branchedor cyclic alkyl group having from 1 to 10 carbon atoms, a linear,branched or cyclic alkoxy group having from 1 to 10 carbon atoms or alinear, branched or cyclic alkoxyalkyl group having from 1 to 10 carbonatoms, R⁷ represents a chained, branched and/or cyclic organic grouphaving from 1 to 30 carbon atoms, which may contain a heteroatom and/oran unsaturated bond, and each R¹, R², R⁴, R⁵, R⁶, and R⁷ and each valueof m and n can be the same or different, provided that R¹ or R² presentin plurality within the same molecule are not a hydrogen atom at thesame time.